"""
继承

- 单继承
- 多继承

=====================================================
单继承

class 类名(父类名):
    类内容体

=====================================================
多继承

class 类名(父类名1, 父类名2, 父类名3......):
    类内容体

=====================================================
"""

print("=====================================================")


# 单继承
class Phone:
    number: None
    cpu: None

    def call_by_4g(self):
        print("开通4g通话")


class Phone2024(Phone):
    ability: None

    def call_by_5g(self):
        print("开通5g通话")


phone = Phone2024()
phone.call_by_4g()
phone.call_by_5g()
